The present invention relates generally to adjustable change in propeller blade shape in order to obtain certain benefits such as reductions in.unsteady blade rate forces.
Attempts have heretofore been made under trailing edge blowing technology to adjust propeller blade loading. Such prior blade adjustment efforts have not been successful because of mechanical complications and reliability problems. It is therefore an important object of the present invention to provide for more effective adjustment of propeller blades involving for example changes in blade camber and pitch by use of magnetostriction.
In accordance with the present invention, propeller blade shape is adjusted by magnetostrictive actuators protectively enclosed within pockets formed within each of the propeller blades. Each of such actuators includes an electrical coil generating a magnetic field within the pocket in surrounding relation to a magnetostrictive rod having opposite ends through which its magnetostrictive deformation is transmitted to the body of the propeller blade under control of electric current to the coil.